1. Field of the Invention
The present invention relates to an anode supported solid-oxide fuel cell based flame fuel cell and, more particularly, to an anode supported solid-oxide fuel cell based flame fuel cell that uses hydrocarbon/air mixture as a fuel source and includes an anode layer, a cathode layer, an electrolyte layer, catalyst layer that can act as a protective layer for the anode layer, wherein the catalyst layer includes Ru, Pt, or other possible catalysts, and an interlayer between the cathode layer and the electrolyte layer, wherein the interlayer can include SDC (Samarium-doped ceria), GDC (Gadolinium-Doped Ceria), or other possible electrolyte materials, such as ScSZ (Sc2O3 stabilized ZrO2), BZY (Yttrium-doped barium zirconate), LSGM (La0.9Sr0.1Ga0.8Mg0.2O3-δ), SNDC (Sm0.075Nd0.075Ce0.85O2-δ), YSZ (Y2O3 stabilized ZrO2), among others.
2. Description of the Related Art
Solid-oxide fuel cells (SOFCs) are all-solid electrochemical devices that directly convert the chemical energy stored in fuel to electricity. Due to a couple of advantages such as high fuel flexibility and non-noble electrodes, SOFCs have received considerable attention.
Up to now, three concepts of SOFCs have been proposed: dual chamber SOFCs (DC-SOFCs), single chamber SOFCs (SC-SOFCs) and no chamber SOFCs (flame fuel cell, FFC), as should be understood and appreciated by those skilled in the art. Compared to DC-SOFCs and SC-SOFCs, FFC is a fairly new concept which was proposed by Horiuchi et al. in 2004. The operation principles of FFC are based on the combination of a flame with an SOFC in a simple “no-chamber” setup (see FIG. 2). The flame serves as a fuel-flexible partial oxidation reformer, while simultaneously providing the heat required for SOFC operation. Taking methane as an example, the burning methane can generate some useful fuels such as H2 and CO, which are the ideal fuels for SOFC. The combustion of methane can generate large amounts of heat to maintain the fuel cell temperature.
FFC shows several distinct advantages including: (1) High fuel flexibility—Gaseous fuels (methane), liquid fuels (jet fuel) and solid fuels (coal) can be applied directly without any pretreated step, which is also beneficial for fuel delivery and storage. Any combustibles can be used directly for FFC operation; (2) Simple setup—No additional heat device is required for initiating the fuel cell. Flame heat release can rapidly achieve the fuel cell operation temperature. The no-chamber design allows the fuel and oxidant to be easily separated; and (3) Rapid start-up—As with the SC-SOFC, the direct-flame fuel cell is capable of rapid start-up and ideal for portable applications. These advantages come with the cost of lower fuel efficiency due to direct chemical oxidation and incomplete fuel utilization. For portable or military applications, for example, rapid start-up and high energy density are more important than the efficiency of fuel utilization. Even with the disadvantage of being a low efficiency method, FFC is considered a viable alternative for creating a power source.
Two types of SOFCs have been employed for FFC: the electrolyte supported SOFC (ES-SOFC), and the anode supported SOFC (AS-SOFC), as should be understood and appreciated by those skilled in the art. ES-SOFC uses a thick electrolyte layer which sustains most of mechanical strength for the entire fuel cell. Fabrication is easy as cathode and anode layers can be directly sprayed on the thick electrolyte layer. Problems for the ES-SOFC based FFC include poor power density and thermal cracking. To address these issues, the AS-SOFCs based FFC were developed.
The AS-SOFC has a thick and porous anode and a thin electrolyte layer which can minimize the ohmic resistance and increase thermal shock resistance of FFC. A previous study has shown that the AS-SOFC based FFC achieved much higher power density and higher thermal shock resistance than those of ES-SOFC based FFC.
The methane/air mixture has been widely used as the flame source for the FFC since it exhibits less coking compared to other heavy fuels. Compared to a pure methane flame, the methane/air flame can perform at higher temperatures and higher concentrations of syngas, which benefits the fuel cell performance. The methane/air based FFC's reported use an ES-SOFC configuration with low power density. In this setup the performance of the FFC was dominated by temperature due to its higher ohmic resistance. For further information, see “High Performance Direct Flame Fuel Cell Using a Propane Flame,” Proceedings of the Combustion Institute, Vol. 33(2):3431-3437 (2011), the entire contents of which are hereby incorporated by reference.
Description of the Related Art Section Disclaimer: To the extent that specific publications are discussed above in this Description of the Related Art Section, these discussions should not be taken as an admission that the discussed publications are prior art for patent law purposes. For example, some or all of the discussed publications may not be sufficiently early in time, may not reflect subject matter developed early enough in time and/or may not be sufficiently enabling so as to amount to prior art for patent law purposes. To the extent that specific publications are discussed above in this Description of the Related Art Section (as well as throughout the application), they are all hereby incorporated by reference into this document in their respective entirety(ies).